Interactive input system's that allow users to inject input (i.e., digital ink, mouse events etc.) into an application program using an active pointer (e.g., a pointer that emits light, sound or other signal), a passive pointer (e.g., a finger, cylinder or other suitable object) or other suitable input device such as for example, a mouse or trackball, are known. These interactive input systems include but are not limited to: touch systems comprising touch panels employing analog resistive or machine vision technology to register pointer input such as those disclosed in U.S. Pat. Nos. 5,448,263; 6,141,000; 6,337,681; 6,747,636; 6,803,906; 7,232,986; 7,236,162; and 7,274,356 and in U.S. Patent Application Publication No. 2004/0179001, all assigned to SMART Technologies ULC of Calgary, Alberta, Canada, assignee of the subject application, the entire contents of which are incorporated herein by reference; touch systems comprising touch panels employing electromagnetic, capacitive, acoustic or other technologies to register pointer input; laptop and tablet personal computers (PCs); personal digital assistants (PDAs) and other handheld devices; and other similar devices.
Above-incorporated U.S. Pat. No. 6,803,906 to Morrison et al., discloses a touch system that employs machine vision to detect a pointer interaction with a touch surface on which a computer-generated image is presented. A rectangular bezel or frame surrounds the touch surface and supports digital cameras at its corners. The digital cameras have overlapping fields of view that encompass and look generally across the touch surface. The digital cameras acquire images from different vantages and generate image data. Image data acquired by the digital cameras is processed by on-board digital signal processors to determine if a pointer exists in the captured image data. When it is determined that a pointer exists in the captured image data, the digital signal processors convey pointer characteristic data to a master controller, which in turn processes the pointer characteristic data to determine the location of the pointer in (x, y) coordinates relative to the touch surface using triangulation. The pointer coordinates are conveyed to a computer executing one or more application programs. The computer uses the pointer location data to update the computer-generated image that is presented on the touch surface. Pointer contacts on the touch surface can therefore be recorded as writing or used to control execution of an application program executed by the computer.
Interactive systems such as those referred to above enable interactive presentations and collaborations. A presenter typically uses a pointer such as a finger or a pen, to select and manipulate displayed graphic objects. The user may add annotations, change colors or fill patterns of graphic objects; and/or move, rotate, enlarge, reduce and generally manipulate displayed graphic objects using certain gestures.
Touch based interactive input systems are sometimes operated by multiple users for collaborative purposes. However, application programs for use with interactive input systems are typically designed with a single user in mind. For example, when two or more users operate a single interactive input system at the same time, a graphic object selected by a first user may be inadvertently de-selected, manipulated or even deleted by a second user making another selection. Such object selectivity may disrupt collaboration between the users.
Improvements are therefore generally desired. Accordingly, it is an object to provide a novel method and apparatus for supporting multiple selections and a novel interactive input system employing same.